Translation technology has become ubiquitous in multilingual classrooms without evidence-based implementation guidance. This mixed-methods study examined K-12 teachers’ translation practices (n = 88 survey; n = 3 district leader interviews), comparing ESL specialists and content teachers to synthesize principles for effective use. Translation use was widespread (81.8%) despite minimal guidance (88.6% lack policies). Common methods included translation applications (89.6%), peer translation (72.2%), and native language texts. ESL specialists reported higher confidence (M = 3.69 vs. 3.18, d = 0.61) and perceived effectiveness (M = 3.76 vs. 3.29, d = 0.56) than content teachers—differences probably attributable to second language acquisition training. Thematic analysis of leader interviews, validated through Structural Topic Modeling, revealed professional development gaps as the strongest convergence (75% alignment). A critical divergence emerged: content teachers rated translation moderately effective, while leaders observed counterproductive practices (11.6% of segments), creating dependency rather than supporting English development. Leaders distinguished productive translation (temporary scaffolding toward English independence) from problematic practices (wholesale content translation). Findings grounded in Contrastive Analysis and Common Underlying Proficiency theory yielded seven evidence-based principles addressing temporary scaffolding, L1 literacy verification, communication versus content contexts, and sustained professional development. The scaffold-versus-crutch framework contributes conceptual clarity for distinguishing productive from counterproductive translation in technology-enhanced multilingual education.